scholarly impact of open access journals

After I wrote about the apparent decline in interest in open source/access/science, one commenter suggested that search volume may be declining as the concepts become more mainstream. Here are those trends again, without open science to obscure the lower search volume terms.

It’s a classic research conundrum - is the effect we are observing real?

I looked into it more using data specifically on open access and open science. I downloaded a list of open access journals from the Directory of Open Access Journals (DOAJ). I also downloaded a spreadsheet of 2011 impact data from Journal Metrics, an offshoot of Scopus that assesses journal impact. Journal Metrics provides two impact measures: Source Normalized Impact per Paper (SNIP) and SCImago Journal Rank (SJR). I will mostly be using SNIP score for this analysis.

According to their FAQ, SNIP “measures a source’s contextual citation impact. It takes into account characteristics of the source's subject field, especially the frequency at which authors cite other papers in their reference lists, the speed at which citation impact matures, and the extent to which the database used in the assessment covers the field’s literature. SNIP is the ratio of a source's average citation count per paper, and the ‘citation potential’ of its subject field. It aims to allow direct comparison of sources in different subject fields.”

There are quite a few more analysis available on the ipython notebook (no coding skills necessary, its a webpage). Here is the link again.

trends in open access

66% of open access journals do not have fees. Only 28% always have a fee - the rest are conditional (or data on fees are missing).

The number of open access journals (OAJ) is steadily increasing. There are 8,597 OA journals according to OAJD, and more are added constantly. It's a strong upward trend!

55% of open access journals are published in English. Spanish is the second most common language at 6%.

A number of journals were started in the 19th century, and some are still published today. Fishery Bulletin, for example, began in 1881 (or 1871, depending on if you believe the website or the DOAJ data) and is still in print.

There are more proportionally OAJ in the life sciences than in physical and social sciences. Not only that, but the gap is quite large - nearly 15% in life sciences, compared to 7% in the other fields.

There are technically more open access journals published in the United States than any other country (but then, there are also more journals overall). Nevertheless, the US lags behind on open access. In fact, the US is not even in the top 50 countries with the highest proportion of OA to closed access journals- just 13% of journals in the US are OA. Colombia, Costa Rica, and Egypt lead the pack, with an open:closed ratio of 35, 26, and 17, respectively.

open access IMPACT

In terms of impact, open access still lags behind non-OA journals. Although the median SNIP value has risen from .34 in 1999 to ,47 in 2011 for OA journals, open access journals have still not caught up to closed journals in terms of impact. On the bright side, there is some evidence the gap may be closing. The median SNIP difference fell from .35 in 1999 to .20 in 2011. If the trend continues, open access journals may soon catch up!

Combining all journals together doesn't quite tell the full story. The academic journal publishing industry is dominated by four countries (US, UK, Netherlands, and Germany). The Big 4 not only publish 38% of the world's academic journals, they also have the highest impact scores. To incorporate this aspect, I separated the scores by country of origin. In Big 4 countries, there is an overall trend of increasing impact for both open and closed journals, with a huge gain for open access journals in particular. In the 79 non Big 4 countries for which DOAJ has data, open access journals continue to yield a higher impact score than their non-OA counterparts.

So on the whole, the picture looks pretty good for open journals. Within individual countries of origin, however, open access impact varies widely. For some countries, open journals have an even higher impact than closed journals. Journals published Brazil, Belgium, India and Japan favor OA, with median SNIP scores nearly double that of closed access journals in those countries.

Unfortunately, journals published in the Netherlands, UAE, New Zealand, and the United States tend to favor closed-access journals. Open access journals have lower impact scores in those countries relative to closed access journals. The Netherlands and the United States are among the aforementioned 'Big 4' countries, which have lots of journals with lots of impact. Continuing OA progress in those countries is an important goal.

Although these findings are more encouraging than the downward trend seen in search volume, my question stands. How do we [improve] the trend, and bring open access into the mainstream?

** Thank you to the commenter who suggested the use of median scores rather than means, which is a better fit for the distribution; I have changed the post accordingly. However, the general trend remains the same for both measures.

This data sources from this post were inspired by this blog post from early 2011, written by Wouter Geritsma.